Mishra A K, Ahluwalia J C
Int J Pept Protein Res. 1981 Nov;18(5):506-12. doi: 10.1111/j.1399-3011.1981.tb03013.x.
Integral enthalpies of solution at very high dilution of sodium salts of N-acetyl amino acids, N-acetyl peptides, and N-benzoyl glycine have been measured in water at 298.15 and 308.15 K. Standard heat capacities of solution at 303.15 K have been derived from the enthalpy of solution data. The peptide backbone-unit (CH2CONH) contribution toward the limiting partial molal heat capacities derived from these experimental results is compared with those obtained from Cop2 of other model compounds, viz. oligopeptides, pyrrolidones, piperidones, diketopiperazine, and amides. Cop2 of the peptide backbone unit observed in the sodium slats of the N-substituted amino acids and peptides is also correlated with the structural details of the compounds and it is concluded that Cop2 contribution of the whole CH2CONH group, rather than that of CONH group, should be used for predicting the heat capacities of polypeptides and proteins in aqueous solution.
已在298.15 K和308.15 K的水中测量了N - 乙酰氨基酸、N - 乙酰肽和N - 苯甲酰甘氨酸钠盐在极高稀释度下的积分溶解焓。从溶解焓数据推导出了303.15 K时的标准溶解热容量。将这些实验结果得出的肽主链单元（CH₂CONH）对极限偏摩尔热容量的贡献与从其他模型化合物（即寡肽、吡咯烷酮、哌啶酮、二酮哌嗪和酰胺）的Cop₂获得的贡献进行了比较。在N - 取代氨基酸和肽的钠盐中观察到的肽主链单元的Cop₂也与化合物的结构细节相关，并且得出结论，应使用整个CH₂CONH基团而非CONH基团的Cop₂贡献来预测水溶液中多肽和蛋白质的热容量。
